A plurality of methods for delivering chemical compounds is known in the art. In recent years large effort has been applied in developing delivery devices in the form of a polymer matrix, in particular hydrogels, with the chemical compound for release embedded in the matrix.
A study by García et al “5-Fluorouracil trapping in poly(2-hydroxyethyl methacrylate-co-acrylamide) hydrogels; in vitro drug delivery studies”, European Polymer Journal 36 (2000) 111-122, describes such delivery devices based on hydrogels where the 5-Fluorouracil was trapped in the gel during its polymerization.
In Ferreira et al. “Evaluation of poly(2-hydroxyethyl methacrylate) gels as drug delivery systems at different pH values”, International Journal of Pharmaceuticals 194 (2000)169-180, the influence of the pH value during loading of Salicylic acid in PHEMA gel was tested. The loading was performed by immersing in a liquid comprising the salicylic acid at various pH values.
Karlgard et al. “In vitro uptake and release studies of ocular pharmaceutical agents by silicon-containing and p-HEMA hydrogel contact lens materials”, International Journal of Pharmaceuticals 257 (2003)141-151 discloses a study of the uptake and release of different chemical compounds in different types of contact lens. The loading was performed by soaking in a liquid containing the chemical compound. It was found that both the uptake and the release were relatively rapid.
Santos et al. “Poly(hydroxyethyl methacrylate-co-methacrylated-β-cyclodextrin) hydrogels: Synthesis, cytocompatability, mechanical properties and drug loading/release properties” ScienceDirect, Acta Biomaterialia 4 (2008) 745-755, describes loading/release properties of hydrocortisone and acetazolamide in the hydrogel. The loading was performed by immersing in liquid containing the drug. It was found that a slow drug release could be obtained.
WO 2005/055972 discloses a drug delivery device comprising a polymeric matrix and a drug distributed within the matrix. The device is essentially free of solvents in particular organic solvents for the drug. The matrix may be an interpenetrating polymer network (IPN) of a large number of different polymer materials.
The drug delivery device is produced by loading the matrix with a drug using a drug carrier in the form of a gas, a supercritical fluid, a high pressure liquid, or a dense gas-like fluid. A preferred drug carrier includes CO2 in a liquid and/or supercritical state. No specific methods are described.
The object of the invention is to provide a novel method of producing a delivery device for delivering a chemical compound, such as a drug where the method provides a high control of the resulting delivery/release profile of the chemical compound from the drug delivery device and where a long delivery time for delivering the chemical compound from the drug delivery device can be obtained.